Everyone's done it: you've got a raging stomachache and you're feeling kind of fatigued, so you search online for the cause of your malady and conclude that you've got cancer. A new study from Microsoft shows that "cyberchondria" is common because when you search for symptoms, the worst case scenario can be the first result—or not representative of the frequency of a serious illness. (For example, searching for a headache will return just as many brain tumor results as caffeine withdrawal, when the chances of a tumor are "infinitesimally small.") Have you decided you're dying after searching for illness symptoms online? Tell us about it in the comments.